Have tried this on mains power in a Victorian flat conversion. The cold air exhaust from the portable air conditioner is vented up the chimney in the lounge. Although it does of course warm the room, cold air will be drawn in (to replace the exhaust air) from other rooms i.e. bedrooms through the sash windows. The effect of this is that on very cold days the temperature in those rooms will drop significantly than if one were using fan heater etc. Experienced this during the UK snow of December 2022 and we did find an answer - electric blankets! With the outside temperature at or above 10 C a 12,000 BTU machine is able to to warm a medium sized room fairly comfortably and can achieve a room temp of 20 C at or below freezing. Tried using a 10,000 BTU machine in the same room with outside temperatures at or below freezing and the machine was not able to warm the room above 17 C.
Thanks Ian, some good points to consider. The exhaust air replacement is certainly important, as you say if you are just sucking cold air back elsewhere that needs consideration. Another reason why a mini split which moves coolant not air between inside and out would probably be a better system than a portable overall.
Some of those 4 in 1 units have the ability to use 2 ducts, one in and one out, which is supposed to help stop that negative pressure problem of sucking in air from outside. I live in an 1960's mobile home/caravan, a worst case scenario for that problem I expect.
Thanks Lloyd. A two hose system definitely looks a better choice. Suppose even for a mobile home the point on mini splits holds with the bonus that avoids the bulk and noisew of a portable unit as well.
I have a portable unit that I use in a permanent set up. To heat I take air from inside, cool it and duct it to out side. Fresh air is drawn in heated and ducted to inside. This is fairly balanced and has 2 advantages. Fresh air and heat recovery from the waste air in the house. This is always warm and by cooling to below the dew point extra energy is recovered. To cool it's used as normal but again fresh air from outside is cooled and the heat is dumped outside. I'd like to use this heat for water heating in the future but it requires a water tank that I don't yet have. Hope that's useful.
Thanks Glynn. Very insightful and air exchange is definitely a good thing. There seems like a lot of stuff out there on air to water but a system that could do air to air for heating as well as offer water heating would be great.
You should convert your air con to a 2 hose system. That was you aren't drawing cold air in to run the thing. It will simply recirculate the heat in the room and heat it.
I went for a mini split install partly because single hose portables don't vent heat outside so have to cool themselves so are less efficient. But for heating I guess that argument doesn't apply. Handy!
Hi Simon, it's ducted through a hole in a wooden door. I have also ducted using the window kit for siting differently but in the other video where I cover the bad bits of using a portable air con for heating, routing a great big ducting pipe is one of them. I think a mini split is a better choice as resolves this and a few others bits.
Hello, it's typically listed in the unit manufacturers specs. So you will typically see how much input Wattage a unit uses and how much heat it will generate. e.g. 1.1kw electricity in for 3.5kw heating output. Sometimes the output may be expressed as BTU, e.g. 10,000 BTU, this can be converted to Watts by dividing by 3.41. Sometimes the specs include a COP (Co-efficient of performance), which is the Output divided by the input. So a COP 3 would mean three times as much heat output as electrical input. Of course COP will fall as temperature drops. Finally of course energy cannot be created it is energy moved from outside to in using the 1kW input in yourfor example. Hence a standard electrical space heater, whether oil filled radiator, fan heater etc. can never have a COP over 1.
I'm trying to figure out if it can be ran as a heater without venting to outside ?, surely it could recirculate the warm room air and make that warmer again ?
Sadly not. The way it works is heat exchange, it doesn't create any new heat energy as with a resistive heater. So one side pumps out hot air. The vent cold.
Air to Air heat pumps........think you forget to mention that in the summer it can cool your house, when my boiler is no longer serviceable i will get air to air
Ha yes, very good point. Absolutely there is also the air conditioner benefit and of course my solar generation excess will cover cooling quite nicely in the summer. My primary aim was really exploring heating efficiency though. Yup next logical step for me will be a mini split system which seems to remove most of the negative sides of a portable system as highlighted in my follow up vid.
Any recommendations for heating a 270 ft sq conservatory? I'm considering 12000BTU two hose unit. What is minimum outside temperature for this to be effective?
It's certainly big enough in terms of output for the room size. Insulation is important though to be effective. As they are not as quiet as other forms of heating you ideally wouldn't want it having to run constantly whilst using the conservatory. Temperature wise a good modern unit should work well into minus temperatures but efficiency falls. Even then though better than the 1 for 1 maximum efficiency of a conventional electric heater. Unit size, purchase cost, blown air breeze and noise are the big cons. Energy efficiency the pro!
Have tried this on mains power in a Victorian flat conversion. The cold air exhaust from the portable air conditioner is vented up the chimney in the lounge. Although it does of course warm the room, cold air will be drawn in (to replace the exhaust air) from other rooms i.e. bedrooms through the sash windows. The effect of this is that on very cold days the temperature in those rooms will drop significantly than if one were using fan heater etc. Experienced this during the UK snow of December 2022 and we did find an answer - electric blankets! With the outside temperature at or above 10 C a 12,000 BTU machine is able to to warm a medium sized room fairly comfortably and can achieve a room temp of 20 C at or below freezing. Tried using a 10,000 BTU machine in the same room with outside temperatures at or below freezing and the machine was not able to warm the room above 17 C.
Thanks Ian, some good points to consider. The exhaust air replacement is certainly important, as you say if you are just sucking cold air back elsewhere that needs consideration. Another reason why a mini split which moves coolant not air between inside and out would probably be a better system than a portable overall.
Some of those 4 in 1 units have the ability to use 2 ducts, one in and one out, which is supposed to help stop that negative pressure problem of sucking in air from outside. I live in an 1960's mobile home/caravan, a worst case scenario for that problem I expect.
Thanks Lloyd. A two hose system definitely looks a better choice. Suppose even for a mobile home the point on mini splits holds with the bonus that avoids the bulk and noisew of a portable unit as well.
I have a portable unit that I use in a permanent set up. To heat I take air from inside, cool it and duct it to out side. Fresh air is drawn in heated and ducted to inside. This is fairly balanced and has 2 advantages. Fresh air and heat recovery from the waste air in the house. This is always warm and by cooling to below the dew point extra energy is recovered. To cool it's used as normal but again fresh air from outside is cooled and the heat is dumped outside. I'd like to use this heat for water heating in the future but it requires a water tank that I don't yet have. Hope that's useful.
Thanks Glynn. Very insightful and air exchange is definitely a good thing. There seems like a lot of stuff out there on air to water but a system that could do air to air for heating as well as offer water heating would be great.
You should convert your air con to a 2 hose system. That was you aren't drawing cold air in to run the thing. It will simply recirculate the heat in the room and heat it.
Thanks Max, for sure that's something for me to look into and would deliver better performance.
I went for a mini split install partly because single hose portables don't vent heat outside so have to cool themselves so are less efficient. But for heating I guess that argument doesn't apply. Handy!
Hi Rob, after assessing this for a few months I think mini splits are the way to go for a number of reasons.
Am I missing something? Where is the ducting for the air? You simply cannot use this in a room without moving heat from the outside to the inside.
Hi Simon, it's ducted through a hole in a wooden door. I have also ducted using the window kit for siting differently but in the other video where I cover the bad bits of using a portable air con for heating, routing a great big ducting pipe is one of them. I think a mini split is a better choice as resolves this and a few others bits.
Pretty good I think.
How do you find the data for the AC’s heating efficiency ?
I.e. the metric you talked about that converts 1kwh to 3kwh of heating
Hello, it's typically listed in the unit manufacturers specs. So you will typically see how much input Wattage a unit uses and how much heat it will generate. e.g. 1.1kw electricity in for 3.5kw heating output. Sometimes the output may be expressed as BTU, e.g. 10,000 BTU, this can be converted to Watts by dividing by 3.41. Sometimes the specs include a COP (Co-efficient of performance), which is the Output divided by the input. So a COP 3 would mean three times as much heat output as electrical input. Of course COP will fall as temperature drops. Finally of course energy cannot be created it is energy moved from outside to in using the 1kW input in yourfor example. Hence a standard electrical space heater, whether oil filled radiator, fan heater etc. can never have a COP over 1.
I'm trying to figure out if it can be ran as a heater without venting to outside ?, surely it could recirculate the warm room air and make that warmer again ?
Sadly not. The way it works is heat exchange, it doesn't create any new heat energy as with a resistive heater. So one side pumps out hot air. The vent cold.
Thanks@@bigskies2202
Air to Air heat pumps........think you forget to mention that in the summer it can cool your house, when my boiler is no longer serviceable i will get air to air
Ha yes, very good point. Absolutely there is also the air conditioner benefit and of course my solar generation excess will cover cooling quite nicely in the summer. My primary aim was really exploring heating efficiency though. Yup next logical step for me will be a mini split system which seems to remove most of the negative sides of a portable system as highlighted in my follow up vid.
Any recommendations for heating a 270 ft sq conservatory? I'm considering 12000BTU two hose unit. What is minimum outside temperature for this to be effective?
It's certainly big enough in terms of output for the room size. Insulation is important though to be effective. As they are not as quiet as other forms of heating you ideally wouldn't want it having to run constantly whilst using the conservatory. Temperature wise a good modern unit should work well into minus temperatures but efficiency falls. Even then though better than the 1 for 1 maximum efficiency of a conventional electric heater. Unit size, purchase cost, blown air breeze and noise are the big cons. Energy efficiency the pro!
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